Adult-onset hypophosphatemic osteomalacia as a cause of widespread musculoskeletal pain: A retrospective case series of single center experience

Table 1 Clinical features of patients with adult-onset hypophosphatemic osteomalacia

	Sex/age	Location of pain	Previous misdiagnosis before OM diagnosis	Weakness (MRC grade)	Gait	Gower sign	Height loss (cm)
1	F/52	Low back, left scapula and chest wall, bilateral mid-thigh	N/A	Hip flexor - 4	Bilateral compensated Trendelenburg gait	(-)	(-)
				Hip abductor - 3
2	M/62	Thoracic back, bilateral chest wall and knee	N/A	Negative	Normal	(-)	170 to 166
3	F/55	Thoracic and low back, bilateral flank, left shoulder	Osteoporotic compression fracture	Negative	Normal	(-)	159 to 153
4	F/76	Low back, right shoulder, left knee	Pathological scapular fracture	Negative	Normal	(-)	145 to 143
5	M/62	Low back, bilateral chest wall buttock, and flank, left heel	Polymyalgia rheumatica. Osteoporosis	NT	Bilateral compensated Trendelenburg gait	(+)	164 to 161
6	F/74	Neck, low back, bilateral shoulder, ASIS, knee, and ankle	Polymyalgia rheumatica. Somatization syndrome	U/E proximal - 4	Bilateral compensated Trendelenburg gait	(+)	150 to 144
				L/E proximal - 4
7	M/54	Low back, bilateral chest wall, right hip, thigh, and knee	Stress fracture of tibia. Osteoporotic compression fracture	L/E proximal - 4	Bilateral compensated Trendelenburg gait	(+)	171 to 165
8	M/61	Low back, bilateral thigh and calf	N/A	U/E proximal - 3	Bilateral compensated Trendelenburg gait	(+)	158 to 151
				L/E proximal - (hip abductor - 0, hip flexor, knee extensor, knee flexor - 4)
				L/E distal - 4

F: Female; M: Male; OM: Osteomalacia; MRC: Medical Research Council; N/A: Not applicable; NT: Not tested; ASIS: Anterior superior iliac spine; U/E: Upper extremity; L/E: Lower extremity.

Table 2 Sites of increased radiotracer uptake on bone scintigraphy

	Spine				Girdles		Long bone (focal)				Long bone (pseudo-reactivation of the growth plate)		Hand and Foot				Rib cage				Others
	C	T	L	S	Scapula	Pelvis	Humerus	Femur	Tibia	Patella	Femur	Tibia	Carpals	Calcaneus	Mid tarsals	Meta tarsals	CV/CT JT	CC jnc	Rosary	Arc	Mandible	Sternum
1		●	●		●		●	●	●	●				●			●	●	●	●	●
2	●	●		●								●	●	●		●	●	●	●	●	●	●
3		●		●														●
4		●	●		●			●	●		●	●		●	●		●	●		●
5	●	●	●	●		●	●							●	●	●	●	●	●	●
6	●	●	●		●		●	●	●	●				●			●	●	●	●	●
7		●	●	●	●	●		●	●						●		●	●		●		●
8		●	●		●	●		●	●		●	●	●	●	●		●	●	●	●

C: Cervical; T: Thoracic; L: Lumbar; S: Sacral; CV/CT JT: Costovertebral/costotransverse joint; CC jnc: Costochondral junction.

Table 3 Etiology, treatment, and outcome of adult-onset hypophosphatemic osteomalacia

	Etiology	Onset to diagnosis (mo)	ADV dose (mg/d)	ADV duration (yr)	Medication change	Time to symptom improvement (mo)	Time to normalization of phosphate (mo)
1	Tumor-induced osteomalacia	25	N/A	N/A	N/A	7 d	2 d
2	ADV-induced nephropathy	25	10	6	Keep ADV	3	Never
3	ADV-induced nephropathy	24	10	11	Change to ETV	0.5	3.5
4	ADV-induced nephropathy	6	10	10	Discontinuation of ADV	3	3
5	ADV-induced nephropathy	9	Unknown	11	Change to ETV	2	8
6	Light-chain nephropathy due to multiple myeloma	14	N/A	N/A	N/A	1	Never
7	ADV-induced nephropathy	27	10	4	Change to ETV	2	9
8	ADV-induced nephropathy	61	10	7	Change to TAF	1	1

N/A: Not applicable; ADV: Adefovir; ETV: Entecavir; TAF: Tenofovir alafenamide fumarate.